new old_time  = -1

public OnPluginEnd()
{
    if(old_time !=-1) 
	{
		SetConVarInt(g_Timelimit,old_time) 
		old_time  = -1
	}
}

public OnConfigsExecuted()
{
    old_time  = GetConVarInt(g_Timelimit)
}

pl_Action(client, args, num)
{
    if(args < 1) {
        switch (num) {
            case 4 : 
			{
				ReplyToCommand(client, "[SM] Usage: sm_extend_time <extend time>")
			}
        }
        return
    }

    decl String:str[16]
    GetCmdArg(1, str, sizeof(str))
    new pl_arg = StringToInt(str)
    if(pl_arg < 0) 
		return

    switch (num) 
	{
        case 4 : 
		{
			SetConVarInt(g_Timelimit,pl_arg+GetConVarInt(g_Timelimit))
		}
    }
}

public Action:ExtendTime(client, args)
{
    pl_Action(client, args, 4)
    return Plugin_Handled
}